New Delhi: The country's natural gas production dropped nearly 15 percent in September as Reliance Industries eastern offshore KG-D6 field continue to decline.

Gas production at 3.36 billion cubic meters in September was 14.8 percent lower than 3.95 bcm a year ago, according to latest data released by the Ministry of Petroleum and Natural Gas here on Thursday.

Fields operated by private firms like RIL saw a massive 34.3 percent drop in output to 1.15 bcm, it said but did not give field-wise data.

"Total six well in Dhirubhai-1 & 3 gas field (in KG-D6 block) and two in MA oil and gas field (in the same area) have ceased to flow due to water/sand ingress," the data said listing reasons for lower output.

India's crude oil production dropped 1.7 percent to 3.06 million tonnes in September with state-owned Oil and Natural Gas Corp (ONGC) reporting a 7.8 percent decline in Mumbai High output at 1.24 million tonnes.

Mumbai High output was lower because of "less than anticipated oil gain from development wells" as well as "less than anticipated oil gain from Vasai East field," the data said.

During April-September, natural gas production was down 12.5 percent at 21.35 bcm while crude oil output was marginally lower at 19.08 million tonnes as compared to 19.22 million tonnes a year ago.

The nation's 20 refineries produced 14.13 million tones of fuel in September, up 11.4 percent from 12.68 million tonnes a year ago. Reliance Industries' Jamnagar refineries reported a 3.9 percent rise in output at 3.04 million tones while Essar Oil saw production more than double to 1.68 million tonnes.

RIL and Essar refineries operated at 109.1 percent and 108 percent of their installed capacities.

During April-September, refinery throughput was up 5.4 percent at 88.17 million tonnes.